The purpose of this study was to establish the reliability and validity of the scores on a brief strengths-based assessment, the 22-item Personal Strengths Inventory (PSI). In Study 1, findings from exploratory factor analysis of 410 adolescents provided evidence for a five-factor solution--social competence (four items), emotional awareness (five items), goal setting (six items), emotional regulation (four items), and empathy (three items). Preliminary evidence of convergent validity was also reported. In Study 2, results from confirmatory factor analysis of 598 adolescents provided additional support for the results obtained from Study 1. Moderate to high reliability coefficients were obtained for the PSI scores. The results are discussed in comparison with other research on social-emotional competence, and further research is suggested. (Contains 3 tables and 1 figure.)